Recent years have seen significant improvements in the fabrication of components for, and in the assembly of, full-moment nodal connections between columns and beams in a plural-story building frame. An excellent illustration of this progress is found in the disclosure of U.S. Pat. No. 6,837,016. Reference is here made to this U.S. Patent for the purpose of providing background information relative to the present invention.
Among the elements of building-frame component and assembly progress which are represented by the disclosure content of that U.S. Patent are that components which enable the creation of robust, full-moment nodal connections between columns and beams may be fabricated under factory and computer-controlled precision conditions for the preassembly of column and beam components which may then be put together on a jobsite quickly, accurately, with immediate, full-moment stability as components are gravity-locked in place without any additional hardware required, and all done in significantly safety-improved conditions which avoid subjecting steel workers to major, long-time, high-level injury exposure.
As those skilled in the building art know, there are various kinds of building frames which not only benefit from the kinds of improvements reflected in the mentioned U.S. Patent, but also frames which introduce certain complexities with respect to nodal connections that must be brought into being between beams and columns where so-called vertical and/or horizontal design offsets need to be addressed. For example, a vertical offset is typified by a building frame which is designed to support a parking structure having multiple, sloping floors connected by sloping vehicle ramps, wherein various beams that extend between next-adjacent columns must be inclined rather than horizontal. A horizontal offset is one which, for example, results when the grid pattern for a layout of columns is other than orthogonal, at least in certain regions of a building frame. Such a horizontal offset may be one wherein next-adjacent columns that reflect an offset are positioned with their “confronting faces” parallel to one another but not directly facing one another, or one wherein a polar grid pattern is utilized to deal, for example, with a curved outside building surface.
Where one or both of these kinds of offsets exists, singular or compound, it is of course necessary to accommodate these offsets by introducing appropriate angular adjustments near the ends of the beams where they connect with columns, so that appropriate full-moment connections can be confidently established. Angular adjustments required to deal with typical vertical offsets lie in the range of about ±8° (relative to the horizontal) in a vertical plane. Angular adjustments needed to accommodate horizontal offsets typically lie in the same range of about ±8° in a horizontal plane. Compound offsets (combined vertical and horizontal) may, of course, be characterized by angular-adjustment needs formed by any combination of these two “singular-character” offsets.
In this kind of a situation, it is, of course, highly desirable to be able easily and relatively inexpensively to accommodate such offsets and such angular construction considerations while at the same time utilizing the various advantages which have been offered to the industry by advances like those which are expressed in the above-referred-to U.S. Patent.
The present invention takes square aim at this situation by proposing a unique, plural-axis, articulated jig structure, also referred to as a beam-offset jig structure, and related methodology, which accommodate manual, or more preferably computer-controlled robotic, welding of beam-end column-interface components, also called beam-end components and beam-end connecting components, to the opposite ends of beams intended to be locked into a building frame between next-adjacent columns through full-moment connections, regardless of whether or not vertical, horizontal or both kinds, if any, of the types of offsets mentioned above are involved. A preferred and best-mode embodiment, and manner of practicing, the present invention, are specifically illustrated and described herein in the context of computer-controlled robotic welding.
It should be understood at this point that the jig-structure (and associated methodology) features of the present invention, which features are illustrated herein in conjunction with a specific type of representative, full-moment, nodal-connection componentry, is not per se linked to the geometry of that componentry. Rather, the structure and methodology of the present invention, as proposed herein, are simply representatively illustrated in this disclosure, in relation to such a particular kind of nodal-connection componentry, in the realm of including complementary receiving structure that allows such componentry, i.e., its particular configuration, to be handled easily during the process of weld attachment to the opposite ends of a beam, with the full recognition that similar complementary accommodating structures could just as well be employed to deal with other specific geometries of nodal-connection hardware.
All of the central features of the invention which one of skill in the art needs to understand in order to practice the invention are fully and clearly disclosable in high-level schematic and stylized drawings, and that is precisely the lead-in approach to disclosure of this invention which is employed below in the detailed description of the invention. Beyond the fully informative schematic drawings, more detailed component drawings are provided simply to illustrate a specific design approach which has been chosen to implement the handling of one illustrative type of beam-end column-interface component (nodal-connection hardware) recently developed as part of a newly proposed, full-moment, beam-column nodal connection. This just-mentioned, newly proposed nodal connection is illustrated and described in currently co-pending U.S. patent application Ser. No. 12/156,252, filed May 30, 2008, for “Halo/Spider, Full-Moment, Column/Beam Connection in a Building Frame”. Reference is here made to this co-pending application for more detailed information regarding this particular kind of nodal connection.
Accordingly, proposed by the present invention, in its preferred form, is a unique, elongate jig structure of the type suggested above, which features an elongate, generally horizontal frame that defines a bed for receiving a pair of longitudinally spaced head-stock and tail-stock structures. Each of these structures is equipped with a conventional, plural-axis (such as a six-axis), computer-controlled, robotic welder disposed in the relevant head-stock or tail-stock structure immediately adjacent specially designed angulation and pivot structure (articulation structure, or motion structure) which is adjustable, in accordance with the features of the invention, to produce proper relative angular positioning between the opposite ends of an elongate beam, such as an I-beam, and a pair of opposite, beam-end column-interface components which are to be employed ultimately in connecting a beam between a pair of columns to produce full-moment connections with those columns. Such beam-end column-interface components can be visualized as each possessing a nominal plane, and the angular positioning which takes place in the practice of the present invention is referred to herein as occurring between such a nominal plane and the long axis of a beam. In the proposed jig structure, the head-stock is equipped, at least in part, with motor-drive equipment to effect certain motion, such as rotation, of certain componentry, with the tail-stock, while having similar, overall motion structure, operating as a slave unit, as will shortly be explained.
The apparatus of the invention is fully capable of dealing not only with conventional, “squared-off”, “non-angular” alignment and pre-positioning between the long axis of a beam and the nominal planes of a pair of beam-end connecting components, where no horizontal or vertical offset needs to be accounted for, but also with infinite (within a range), pre-welding angular alignment and pre-positioning of beam-end components relative to a beam to deal with one or both kinds of offsets, singularly or in combination. In most instances, the jig structure, if equipped to accommodate angular beam-end connecting-component adjustments in the range of about ±8° for each kind of offset, will adequately handle all typical offset conditions. The jig structure illustrated herein is so equipped.
Thus, and as will be seen from the detailed description of the invention which appears below, the mentioned head-stock and tail-stock structures each includes (a) a main rotator which is capable of rotating on what is referred to herein as the principal long axis of the jig structure of the invention, which axis is also called the jig-rotation axis and the rotation axis, (b) a rocker, or rocker structure, which is carried on that rotator and which allows for limited, reversible, angular rocking about a rocker axis which is orthogonal to, and which intersects, the jig-rotation axis, and (c), what is referred to herein as a beam-end, column-interface-component gripper which is mounted on the rocker for independent 360° rotation about a rocker-rotation axis that orthogonally intersects the rocker axis at the location where the rocker axis intersects the jig-rotation axis.
This unique arrangement of componentry allows for appropriate, compound angular adjustment, if such is necessary, effectively in an infinite adjustability way to accommodate all arrangements of angular disposition which are normally expected may be required between the long axis of a beam and the nominal plane of a beam-end column-interface component in order to accommodate not only squared-off ultimate disposition of that beam, but also angular offset disposition as desired.
Within the apparatus of the invention, and as was stated more generally above, the gripper just mentioned is one which, while illustrated herein specifically shaped to deal with one illustrative kind of beam-end column-interface component, will of course be configured, as necessary, to deal with whatever particular-geometry beam-end component may be the kind which is intended to be joined by welding to the end of a beam.
The above-mentioned features and advantages presented and offered by the jig structure of the present invention will become more fully apparent as the detailed description thereof which shortly follows is read in conjunction with the accompanying drawings.